How to store JavaScript variable value in JSP session

Pass that variable to Servlet using ajax OR set it in some hidden field when form will get submit it will also get POSTed.

Your best bet is to just store the value in a cookie. Both client side javascript and server side jsp can access cookies.

There should be a natural flow to your program, so that you don't have to have a mechanism specifically for storing variables just for the sake of storing variables. By that I mean that if you are storing a userName, it should be while login is occurring, or if you are obtaining contactInfo, then you should have a servlet specifically for that purpose. Regardless, here is a three part answer to your question. It is very general and non-specific, but will accomplish what you want once fleshed out: Here is the web.xml file: <servlet> <servlet-name>StoreVariableServlet</servlet-name> <servlet-class>tests.servlets.StoreVariableServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>StoreVariableServlet</servlet-name> <url-pattern>/storeVariableServlet</url-pattern> </servlet-mapping> Here is the jQuery Code: $.ajax({ type: "POST", url: "/storeVariableServlet", data: ({ variable : $(variableName).val() }), success: function(){ alert("Success"); } }); Here is the Servlet Code: String variableToBeStored = request.getParameter("variable"); HttpSession session = request.getSession(); session.setAttribute("variableXYZ", variableToBeStored);